Changes between Version 212 and Version 213 of UvmatHelp
- Timestamp:
- Dec 15, 2022, 7:12:00 PM (22 months ago)
Legend:
- Unmodified
- Added
- Removed
- Modified
-
UvmatHelp
v212 v213 609 609 To calibrate at once a set of experiments, a better alternative is the command '''[REPLICATE]'''. Open a folder '''Campaign''', parent of the folders '''Experiment''' to treat. The GUI '''data_browser.fig''', also described in [#a3.7Dataorganisationinaproject section 3.7], then pops up. A two-column display appears, with the list of '''Experiments''' on the left and the list of corresponding '''[!DataSeries]''' on the right. Select the list of experiments to calibrate, and a single camera name in '''[!DataSeries]''', then validate by pressing '''[OK]'''. 610 610 611 -''' 3D calibration''': 3D projection is handled by the options in '''[calib_type]''' '3D_lin' or '3D_quad' (if non-linear distortion is significant). By default, the set of calibration points is assumed to be contained in a single plane ''z''=0. For a correct determination of the 3D features, the normal to this plane must be tilted with respect to the line of view. Otherwise this problem of indetermination can be resolved by using a set of (typically 5-10) calibrations images using a plane grid with different tilting angles (for precision the grid must cover a large area of the view field). On each image, get calibration points with the tool '''[!Tools/Detect grid]''', introducing the appropriate grid mesh. Do not fill info on ''z'' coordinates. Store the points each time (without applying calibration at this stage), which fills the list [!ListCoordFiles] of file names. Then introduce a last grid image which will be considered as defining the orientation of the ''z'' axis, perpendicular to the grid. Detect points on this last image, but instead of storing them, apply the calibration with the option 3D_linear or 3D_quadr. A non-zero ''z'' position of this grid can be introduced by a z translation performed with '''[!Tools/Translate points]'''. 611 -''' 3D calibration''': 3D projection is handled by the options in '''[calib_type]''' '3D_lin' or '3D_quad' (if non-linear distortion is significant). By default, the set of calibration points is assumed to be contained in a single plane ''z''=0. For a correct determination of the 3D features, the normal to this plane must be tilted with respect to the line of view. Otherwise this problem of indetermination can be resolved by using a set of (typically 5-10) calibrations images using a plane grid with different tilting angles (for precision the grid must cover a large area of the view field). On each image, get calibration points with the tool '''[!Tools/Detect grid]''', introducing the appropriate grid mesh. Do not fill info on ''z'' coordinates. Store the points each time (without applying calibration at this stage), which fills the list [!ListCoordFiles] of file names. Then introduce a last grid image which will be considered as defining the orientation of the ''z'' axis, perpendicular to the grid. Detect points on this last image, but instead of storing them, apply the calibration with the option 3D_linear or 3D_quadr. A non-zero ''z'' position of this grid can be introduced by a z translation performed with '''[!Tools/Translate points]'''. It is generally convenient to do all these calibrations in air. Then transposition to water is done by the tool 'set_slice', see section 8.3. 612 612 613 613 -''' Intrinsic parameters''': the previous procedure first determines the extrinsic parameters which characterize the camera optics (focal lengths and nonlinear deformation parameter). Then the extrinsic parameters, translation and rotation of the camera with respect to the reference grid, are determined on the last grid image. If the same optics is used in a new experiment, it is possible to skip the multiplane detection, importing the intrinsic parameters from a previous <!ImaDoc> file by the menu bar tool '''[Import.../Intrinsic parameters]''', then applying the calibration with the option '3D_extrinsic' with the reference grid image only. … … 656 656 657 657 * <!PointCoord>: [x y z X Y] , where x,y,z are the physical coordinates of each point, X Y its image coordinates. 658 659 The parameters defining the slice positions are in the XML element <!ImaDoc/Slice> as follows:660 661 * <!NbSlice>: nbre of slices 658 659 The parameters defining the slice positions are in the XML element <!ImaDoc/Slice > as follows: 660 661 * <!NbSlice>: nbre of slices 662 662 663 663 * <!CheckVolumeScan>=0 for the multilevel case (position is given by index i modulo !NbSlice ), =1 for volume scan (position is given by index j) … … 665 665 * <!SliceCoord>: [x y z] positions (!NbSlice lines) of the !NbSlice planes. For volume scan with translation, x=y=0, z= slice height. For angular scan, [x,y,z]=[coordinate on the rotation axis]. 666 666 667 * <!SliceAngle> set of !NbSlice angles. !SliceAngle(i,1) = angle of rotation around x axis for plane #i . !SliceAngle(i,2) = angle of rotation around y axis for plane #i. ( !SliceAngle(i,3)=0 is not used) 667 * <!SliceAngle> set of !NbSlice angles. !SliceAngle(i,1) = angle of rotation around x axis for plane #i . !SliceAngle(i,2) = angle of rotation around y axis for plane #i. ( !SliceAngle(i,3)=0 is not used) 668 * <! InterfaceCoord> =[0 0 h] where h is the z coordinate of the upper surface ( top view assumed) 669 * [wiki:RefractionIndex <RefractionIndex]> index of refraction of the fluid (=1.33 by default), to use if clibration was done in air. 668 670 669 671 == 9 - Masks and grids == … … 838 840 The button '''[TEST]''' allows the user to witness the correlation as a live plot. It first opens the source image in a new figure '''view_field'''. By moving the mouse in the figure, the local correlation box and the corresponding search box are drawn in the image, and the 2D correlation result then appears in a new figure 'Figure1 Image Correlation' which automatically pops up. It is possible to freeze the current correlation plot, and get the values in the Matlab work space, by left mouse selection. The figure belows shows the correlation process and the '''[!SearchBox]''' and '''[!CorrBox]''' explained before. 839 841 840 [[Image(civ1_test.jpg)]] [[Image(Correlation for PIV.png)]]842 [[Image(civ1_test.jpg)]] [[Image(Correlation for PIV.png)]] 841 843 842 844 The grid determines the positions of measured velocity vectors: it sets the central positions of the correlation boxes (in pixels) for the first image. A default regular grid can be set by the meshes '''[num_Dx] ''' and '''[num_Dy]''' (in pixels). Alternatively a custom [#a9.2Grids grid] can be stored in a text file and selected by the check box '''get grid'''. This is convenient to limitate the processing to a subregion or to fine tune the resolution. … … 1027 1029 ---- 1028 1030 == 13 - Editing XML files with the GUI editxml == 1029 This GUI ''' editxml.fig''' visualises and edits XML files. It is automatically called by the browser of ''' uvmat.fig'''when a file with extension .xml is opened.1031 This GUI ''' editxml.fig''' visualises and edits XML files. It is automatically called by the browser of ''' uvmat.fig''' when a file with extension .xml is opened. 1030 1032 1031 1033 When an input file is opened, editxml detects the title key, e.g. <!ImaDoc>, and looks for the corresponding XML schema (e.g. {!ImaDoc.xsd} ). This schema is sought in the directory defined by <!SchemaPath> in the installation file {PARAM.xml} of UVMAT. If the schema is found, the hierarchical structure and keys given by the schema are diplayed. Otherwise the keys of the XML file are displayed.